have a 97 exp,(auto 4wd) 4.0 push rod, the 4wd keeps kicking in, i have replaced the gem module twice(once speedo problem) and now this time with one from a pull ur parts place, part numbers matched, as in the first time. but this one is doing the same. everything else works fine. i can hear the gem actually make clicking sound, what sends the info to gem ie wheel slip to make it engage the 4wd . i have misplaced my owners manual so i can not pull the 4wd fuse to stop it, the gas mileage is killing me, any help would appr. thanks
BT

 

If it's sensing wheel slip, maybe one of your wheel speed sensors went bad.

Ford manuals
https://owner.ford.com/servlet/Conte...OwnerGuidePage

 

3 causes to check

any tire low on air and causing a speed differential or,
Hall sensors in T/C dirty, and
A/T fluid in T/C dirty/old, plates sticking.. ...Philip

 

belive i might have found it, is the hall sensor the one on bottom three wires just under yoke, one of the wires has the insulation coming off it and bare wire. i moved the wire and test drove it seemed to be working fine.now. looks like that sensor is hooked directly into the main harness plug in to the transmission

 

There are 2 hall sensors on the back of the T/C, pull them both and clean, If damaged replace...

Change the fluid in the T/C, open the fill plug before the drain, fill with ATF... Philip